The Role of Phytophthora cryptogea and Waterlogging in a Decline of Pinus radiata

Abstract

Experiments to determine the roles of Phytophthora cryptogea and waterlogging in a decline of Pinus radiata showed that the fungus affected young pines up to 1 year old when associated with water- logged soil. In drier soil, similar plants were affected by the fungus only when they had originally been transplanted to the test pots. However, waterlogging affected both transplanted and non-trans- planted young trees in both the presence and absence of the fungus. Thus waterlogging is an important factor in the decline of young Pinus radiata. A similar situation probably exists with regard to older trees growing on very wet sites.